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Topic Review (Newest First)

01-10-2011 12:46 PM

sbchevfreak

Quote:

Originally Posted by DanielC

My 1996 Aerostar van is EEC IV, but because it is a 1996 (or later) it is OBDII. It does have a catalyst monitor.

DUH, I had brain fart, lol! I forgot EEC IV carried over into the OBD II years, my bad. Once OBD II compliance came into effect, catalyst monitoring became manditory. In the OP's case, he does not have it, and IMHO, should focus his efforts on the EGR and EVAP faults.

01-08-2011 08:55 PM

DanielC

My 1996 Aerostar van is EEC IV, but because it is a 1996 (or later) it is OBDII. It does have a catalyst monitor.

01-08-2011 08:51 PM

DanielC

I guess a refresher term at a local community college, 2 years ago, studying fuel systems and emission control systems paid off. The last time I was at a community college, cars had carburetors, and most distributors still had points under the cap. But most of the cars had alternators, not generators.

01-08-2011 08:27 PM

sbchevfreak

The 1990 ford EEC system is still OBD I, so no misfire monitor, in fact a misfire will read as a false lean and open up the injector pulse width. A converter is not needed for ECM operation, as the EEC III/IV systems did not use a catalyst monitor. The #1 thing turning on the MIL is the EGR fault. These are known for the EGR valve position sensor failing, as well as DPFE faults. Get the cooling system fabb'd up, and do a full KOER code read, and give us the resulting numbers. This will help narrow the search to the proper system. Also, do a quick visual on the vacuum lines, the early 90's fords had a whole bunch of them. IIRC, the line to the EGR is a green line, with computer controlled vacuum supply.

01-08-2011 08:07 PM

LATECH

Quote:

Originally Posted by DanielC

The Thermactor is the air pump, fresh air into the exhaust system,
EGR is exhaust gas recirculation.

They are pretty independent of each other, but keep in mind, everything on modern engines is interrelated.
The air pump pumps fresh air into the exhaust, and it helps burn off unburnt hydrocarbons
and convert CO to CO2, in the catalytic converter.

EGR is used mainly to reduce oxides of nitrogen, from the engine. It can also be used in some conditions to reduce spark knock.

Dan C got a 100 on this one.Exactly perfect. I also like his suggestion to keep the evap functional,especially if you garage park your car.You wont smell fuel in the garage if it is working properly. Kudos Dan C

01-08-2011 02:19 PM

DanielC

The Thermactor is the air pump, fresh air into the exhaust system,
EGR is exhaust gas recirculation.

They are pretty independent of each other, but keep in mind, everything on modern engines is interrelated.
The air pump pumps fresh air into the exhaust, and it helps burn off unburnt hydrocarbons
and convert CO to CO2, in the catalytic converter.

EGR is used mainly to reduce oxides of nitrogen, from the engine. It can also be used in some conditions to reduce spark knock.

01-08-2011 01:45 PM

johnhawes

Thanks again latech, you probably saved me time, money, and a lot of fustrution with the information about a marine computer, i do have both O2 sensors connected. One of the fault codes is Thermactor air system fault, and another is EGR valve not operating properly. Could the EGR fault be a result of the Thermactor system fault or vise versa?
Thanks,
John

01-08-2011 01:35 PM

johnhawes

Thanks latec, i have learned what the BOO switch's function is i had no idea what it was for.
John

01-08-2011 11:54 AM

LATECH

Also a 1990 ford had an AOD not a c-4. If it has a lockup converter operated by the ecm and not just by hydraulic then you will need the BOO switch.Otherwise it shouldnt pose any issue. (Brake On Off)

01-08-2011 11:50 AM

LATECH

Quote:

Originally Posted by johnhawes

Thanks Guys,
Both good suggestions, probably should consider installing the smog pump and catalytic converter but I'll also look into getting a computer off a boat or something that doesn't have all the smog stuff. I don't know what to do about the brake on/off switch though.
My worry is that the computer can't do it's job unless it has the input from all of the sensors. The whole point in going EFI is for efficient engine operation.
Thanks again for your input.
John

A marine computer for any year wont give good performance as the fuel mix and timing curves are WAY different due to the way a marine engine moves a boat through water. Dont waste your time.If it isnt setting any sensor codes dont worry about it like F Bird said.
No cats and no smog pump will only affect performance in a minor way. You would probably not ntice. You do want an O 2 sensor(or both) hooked up. If it had down stream sensors, leaving them out wont affect performance , all they do is measure cat health.

01-08-2011 11:41 AM

DanielC

Here is something else to consider. The charcoal cannister. It would be another system to hook up, but it does not reduce the power output of the engine. The engine does purge any vapors from it, and recycles then back into the engines intake manifold, and the engines computer, with the O2 sensor reduces the amount of time the injectors are "on" because of the gas vapors coming out of the cannister.

I think is is better to gain the slight mileage, from having a sealed fuel tank, than just to dump the vapors out into the air.

01-08-2011 07:28 AM

johnhawes

That makes sense, thanks.
John Hawes

01-07-2011 05:56 PM

86GMC

ford bo/o switch is the one on the pedal that controls the brake lights, if I remember right. Computer uses it as an input for cruise disable. Dont remember if brake lights are a computer output or not, but not an issue if you have a standalone light control circuit

01-07-2011 03:47 PM

johnhawes

o

The engine and computer are from a 1990 Crown Victoria and apparently that model has some type of brake on/off sensor that the computer reads as that is one of my KOER trouble codes.
So far I have only been able to run the engine for short periods because the radiator assembly hasn't arrived yet, engine running test are to be made at normal operating temperature. I am hoping that i may loose some of the trouble codes then.
Thanks,
John

01-07-2011 03:09 PM

DanielC

What brake on/off switch? Was it just for the emergency brake being on, or something on the hydraulic circuit?

The catalytic converter is not needed for the most efficient engine operation, but the engine does have to have misfire detection to avoid catalytic converter damage. However, the engine would run a lot cleaner with the cat, and the air pump.

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